In any roadway or construction project, safety is paramount—especially when it comes to protecting drivers, workers, and infrastructure from high-speed collisions. One of the most critical components in roadway safety is the crash cushion system, also known as an impact attenuator. These systems are designed to absorb the energy from a vehicle collision and prevent damage to permanent structures, as well as reduce injury severity to vehicle occupants.
But with various options available on the market, how do you determine which crash cushion system is right for your project? This guide breaks down the factors you should consider when selecting the ideal crash cushion for your specific application.
What Is a Crash Cushion System?
A crash cushion system is a protective barrier placed in front of fixed roadside hazards, such as concrete barriers, toll booths, bridge piers, and gore points at highway exits. Its primary purpose is to absorb and dissipate the kinetic energy of an impacting vehicle, guiding it to a stop or redirecting it away from danger.
These systems come in both permanent and temporary formats and are built using different materials and technologies—ranging from water-filled units to proprietary systems made from steel, plastic, or aluminum components.
Key Factors in Selecting the Right Crash Cushion
1. Type of Roadway or Environment
Your project location plays a major role in choosing the appropriate crash cushion. For instance:
- Highways and freeways require high-performance, high-speed rated systems capable of handling impacts at speeds of 70 mph or more.
- Urban streets or parking facilities may need compact or low-speed attenuators.
- Work zones often benefit from temporary or relocatable systems that are easy to install and remove.
2. Speed and Impact Severity
Crash cushions are rated for specific impact conditions. Systems must comply with performance standards such as those set by NCHRP Report 350 or the newer Manual for Assessing Safety Hardware (MASH). Make sure your selected cushion is tested for the anticipated speed and vehicle types expected at the site.
3. Traffic Volume and Flow
Higher-traffic areas may necessitate robust systems that offer multiple hit capabilities without extensive maintenance. In contrast, low-volume rural roads may not require the same level of durability or reset speed.
4. Reusability and Maintenance
Modern crash cushions often allow for easier reinstallation and repairs after minor impacts. Some systems are designed to be reusable after a crash with minimal intervention. Evaluate the lifecycle cost—not just the purchase price—when making your selection.
Types of Crash Cushion Systems
Here’s a look at the most common types available today:
- Gating vs. Non-Gating Systems: Gating systems allow vehicles to pass through or over them in low-speed impacts, while non-gating systems stop or redirect vehicles. Non-gating is typically preferred for higher-speed roadways.
- Redirective Systems: These not only absorb impact but also redirect a vehicle away from the hazard. They are essential for protecting fixed structures on highways.
- Non-Redirective Systems: Generally used in low-speed zones or temporary work zones. They absorb energy but don’t redirect the vehicle.
- Water-Filled Barriers: Common for temporary use, these are easy to transport and set up but may be less effective for high-speed impacts.
- Sand Barrel Arrays: Traditional and effective for stationary object protection, especially where a gradual stop is necessary.
Installation Considerations
Proper installation is critical to the effectiveness of a crash cushion. Systems must be mounted per manufacturer specifications, anchored if required, and located at the correct offset from the hazard. For temporary systems, ease of deployment and repositioning is an advantage—particularly in dynamic construction environments.
Work with certified traffic safety contractors and ensure your cushion selection aligns with your state’s Department of Transportation (DOT) requirements.
Compliance and Safety Standards
Crash cushion systems should meet federal and state testing standards. In the U.S., the MASH (Manual for Assessing Safety Hardware) guidelines are currently the standard. Always verify that the system you’re choosing has passed MASH testing and is listed on your state’s qualified products list.
Choosing the right crash cushion system for your project requires a careful evaluation of the roadway conditions, traffic flow, impact expectations, and installation requirements. Whether you’re planning a long-term highway project or need a temporary solution for a construction zone, there’s a crash cushion designed to meet your needs.
Partnering with an experienced traffic safety consultant or contractor can help ensure you’re not only compliant but also providing the highest level of safety for motorists and workers alike. When selected thoughtfully, crash cushion systems are a reliable and proven method to reduce injuries and save lives in the event of a roadway accident.